/**
 * Copyright (C) 2015 lib
 * Copyright (C) 2013 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package diandiansong.library.tabviewpager;

import android.view.animation.AccelerateInterpolator;
import android.view.animation.DecelerateInterpolator;
import android.view.animation.Interpolator;


abstract class SmartTabIndicationInterpolator {

 public static final SmartTabIndicationInterpolator SMART = new SmartIndicationInterpolator();
 public static final SmartTabIndicationInterpolator LINEAR = new LinearIndicationInterpolator();

 static final int ID_SMART = 0;
 static final int ID_LINEAR = 1;

 public static SmartTabIndicationInterpolator of(int id) {
   switch (id) {
     case ID_SMART:
       return SMART;
     case ID_LINEAR:
       return LINEAR;
     default:
       throw new IllegalArgumentException("Unknown id: " + id);
   }
 }

 public abstract float getLeftEdge(float offset);

 public abstract float getRightEdge(float offset);

 public float getThickness(float offset) {
   return 1f; //Always the same thickness by default
 }

 public static class SmartIndicationInterpolator extends SmartTabIndicationInterpolator {

   private static final float DEFAULT_INDICATOR_INTERPOLATION_FACTOR = 3.0f;

   private final Interpolator leftEdgeInterpolator;
   private final Interpolator rightEdgeInterpolator;

   public SmartIndicationInterpolator() {
     this(DEFAULT_INDICATOR_INTERPOLATION_FACTOR);
   }

   public SmartIndicationInterpolator(float factor) {
     leftEdgeInterpolator = new AccelerateInterpolator(factor);
     rightEdgeInterpolator = new DecelerateInterpolator(factor);
   }

   @Override
   public float getLeftEdge(float offset) {
     return leftEdgeInterpolator.getInterpolation(offset);
   }

   @Override
   public float getRightEdge(float offset) {
     return rightEdgeInterpolator.getInterpolation(offset);
   }

   @Override
   public float getThickness(float offset) {
     return 1f / (1.0f - getLeftEdge(offset) + getRightEdge(offset));
   }

 }

 public static class LinearIndicationInterpolator extends SmartTabIndicationInterpolator {

   @Override
   public float getLeftEdge(float offset) {
     return offset;
   }

   @Override
   public float getRightEdge(float offset) {
     return offset;
   }

 }
}
